The present invention generally relates to services, and more particularly to reputation services that maintain the privacy of users.
General purpose reputation services are difficult to implement with robust protection from fraud and previously impossible to implement without specific knowledge of unique or demonstrably rare information on contributors to the system. Current successful reputation systems are maintained by providers, such as, Ebay and Amazon, which depend on the ability to link personal information, including unique credit card numbers, names, and addresses, to prevent abuse. Abuse attacks on reputation services are common. Typical attacks are Sybil attacks and Astroturfing.
Existing reputation systems cannot track individuals across multiple providers of goods and services, thus making it possible for individuals to provide false positive or negative feedback affecting the reputation of providers with no concern for their own reputation.